Accordion bellows construction



Jan. 22, 1952 5 SLQAN 2,583,308

ACCORDION BELLOWS CONSTRUCTION Filed April 19, 1946 PI. E

, INVENTOR. [PW/9R0 [f 510/7,

26 Y 25 j%/ z 11 z 7 mmwszis Patented Jan. 22, 1 952 UNITED STATES PATENT ACCORDION BELLOWS CONSTRUCTION Edward G. Sloan, Madison, Wis.,-assig-nor..to The Rudolph Wurlitzer Com any, Chicago; Ill /a corporation Application Arril'w. isreiserial 'No. 663,260

and the usual unsightly metal or leather corner pieces are eliminated. The bellows; while maintaining its required flexibility at the exterior folds and corners will-not only be reinforced and protected but willpresenVa-more sightly appear ance than heretofore.

A'feature of'the invention resides in the construction and method employed, such as to facilitate and render more economical the production of such bellows. In accomplishing the above, the substantially rigid Vinyli te sheets are adhered to a pair of single sheets of air impervious cloth or fabric which also serves to form the hinge or fold construction of the diaphragms, the outer folds and the beading thereof comprising in effect three separate hinges which together make a free'acting pivot for the substantially rigid portion of the fold such as to-keep the beading in the proper relation'to-the bellows as a whole.

With the above construction onlyone air tight scam in the air impervious fabric is required,

said fabric being sofolded as to provide the inner and outer hinge folds such as will not Joe-stressed in the opening and closing of the bellows. The

plastic reinforcing strips, particularly the'bead or roll extending about the outer=folds and corner sections, also serve to *protect'the fabric and materially improve the appearance'of the -be1- lows as a whole.

The full nature of the invention will be understood from the accompanyir-lg drawingsand'the following description-andclaims:

Fig. 1 is a perspective view showinga port-ionof the bellows with the attached treble-and bass boxes.

Fig. 2 is a-sectio-n through a portion-of "the bellows taken on-the line 2---2 of Fig. 1 showing them in collapsed position.

Fig. 3 is the'same as Fig. 2, showing aportion of the bellowsidilated.

Fig. 4 is a longitudinal section-through the layers of materialb fore forming-and folding the bellows.

" 9 Claims. (Cl. 137-i-156.5)

Fig. 5- is a -plan-view of one of the diaphragms showing a portionthereof cut away to provide a corner section, and with layers of material brokenaway.

Fig-6 is-a plan view of a formed corner section of one of the diaphragms. I

In the drawings there is shown one applicathan of the bellows wherein it isrnounted .in an accordion comprising a bass box Ill, treble;box H,'a key bed IZ'and keys l3. .Secured between the boxes 10 and H in the usual manner there is provided the bellows M.

The bellowsM is constructed from a series of "layers of flexible material secured together in the manner best illustrated in Figs. 4 and 5. Thus, each diaphragm comprises an inner layer or "strips of airv impervious fabric orcloth l5 over which there is bonded the strips l 6 of a substane tially rigid plastic such as Vinylite. As shown in Figs. 2, 3 and 4 the strips 15 of Vinylite are formed along their adjacent edges with an in.- wardly curved portion W, said curved portions being turned inwardly and arranged adjacent each other slightly spaced apart to :provide a slight outer hinge gap therebetween as indicated at 18. The gap between the inturned curved portions H is spanned so that each adjacent pair of said strips 15 are hingedly secured together by said inner layer or strips of fabric 15. Thus, the sheets 15 are secured and hinged together by-the fabric 15 to provide a substantially rigid outer fold having aflexible hinge joint. However,

the fabric l5,-al-though illustrated herein inthe form of a continuous :sheet, ma serve equally well in the form of a series of strips sufficiently wide to span the hinge gap. E8 'to provide the flexible outer hinge connection between the plastic strips I6.

A continuous over-all outer layer ll] of .air impervious fabric is secured over the opposite or outer faces of the plasticstripsilfi and is formed -with an' outwardly extending looped portion .20 envelopingthehinge gap l8 between the curved portions I1 of said strips l6. Secured to said looped 1 portion .20 of :the vfabric :sheet l9. there is a plastic or IVinylite bead .2l U-shaped in cross section. Thus, therlooped portion 20 and the bead Z-I-span the'hinge gap l8 to cover and protect it exteriorly thereof.

Said beads 2! are of-such width that when the accordion is in collapsed position, as shown in Figs. 1 and '2, their side walls may abut each other and thereby-maintain the outer :bellowsfolds in "even- --ly spaced relation.

fiverlying andfsecured to the sheet. of fabric [9 there are outer strips 22 of said plastic material. Said strips 22 form the outer protective surface of each of the diaphragms and lie with their outer edges approaching the bead 2| on each side and in close proximity thereto, but spaced therefrom. The inner or remote edges of said strips 22 lie adjacent to but slightly spaced from each other to permit of and provide the slight inner hinge gap '23. e

By means of the above construction the diaphragms of the bellows are joined together to provide an outer fold hinge at l8 and an inner fold hinge at 23, as illustrated in Figs. 2-4. The diaphragms intermediate said hinge portions or folds are of alternate layers of air impervious cloth l5, l9, and alternate layers of the semirigid plastic strips I6, 22, such as Vinylite. Thus, the intermediate portions of the cloth are held substantially rigid and protected by the plastic strips, while the cloth sheets or strips l5, l9 permit of the flexing or hinging between said plastic strips at I8, 23. This is permitted at I8 by the gap between the curved portions I? of the sheets l6, both fabric sheets or strips |5, |9 serving as a double reinforcing hinge at 23. The hinge at I8 is further protected and enclosed by the double hinge portions provided by the fabric sheet If! between the bead 2| and adjacent edges of the strips 22. The enlarged looping of the fabric sheet |9 also supports and secures in place said protective decorative and spacing bead 2|.

In constructing the bellows, the several strips of plastic are cut to proper size to permit of the above arrangement, and mounted over the single sheet of fabric IS, the sheet or strips l of fabric being placed over the adjacent curved portions I! of the plastic strips l6, as best illustrated in Figs. 4 and 5, whereupon they are bonded together in the well-known manner under heat and pressure. However, in order to form the corners of the bellows, as shown in Fig. 6, the plastic strips [6, 22 are cut away at the proper spaced intervals to permit formation of the four or. more corners. Said cut away portion of the strips is indicated in Figs. 5 and 6 at 24 wherein tapered notches 25 are formed to provide the corresponding radially projecting fingers 26. This permits the folded diaphragms to be bent at a 90 degree angle to each other to form the corners with a V-shaped gap therebetween embracing the pleated folds 27 of the fabric sheet l9. In so bending the folded diaphragms to provide the corner sections thereof, the plastic beads 20 are drawn into curved formation about a radius of curvature developed by fingers 26, as shown in Fig. 6. This is accomplished where necessary by conditioning them through the usual application of heat.

As a result of the above structure and method of producing bellows, the entire assembly of materials may be pre-cut .and laid out, bonded together in the flat to provide a series of diaphragms, and then folded along their hinge gaps I 8,23 into the bellows structure, as above described. The resulting construction of the bellows is such that the fabric material is protected throughout substantially its entire area and strengthened by the plastic strips. But more particularly the edges of the outer hinge folds are reinforced and protected against wear and dam-. age, as well as the corners thereof by the continuous plastic beads 2|. Said plastic beads add materially to the external appearance of the bellows in that the beads 2| extend about the corner sections, as distinguished from the usual.

4 metal or leather protective corner pieces. Also, when the bellows is collapsed the plastic beads 2| provide a uniform spacing such as to give an evenly disposed scalloped appearance to the exterior surface.

The invention claimed is: 1. A rectangular bellows having a series of diaphragms formed of a sheet of flexible material,

' folded to provide inner and outer hinge folds for said diaphragms along their inner and outer edges respectively, said flexible material being folded at intervals on itself in the plane of the diaphragms to provide corner sections, and a plastic bead curved in cross section bonded to said flexible material along each outer hinge fold thereof and formed to extend about said corner sections to provide a continuous peripheral protective element for each of the outer hinge folds.

2. A rectangular bellows having a series of diaphragms formed of a flexible air impervious material folded to provide inner and outer hinge folds therebetween and corner sections therefor, and a peripheral head of plastic material curved in cross section bonded to said flexible material along each outer hinge fold thereof for embracing and protecting said fold, said bead being longitudinally curved to extend about the corner sections of said diaphragms.

3. A rectangular bellows comprising a series of diaphragms formed from a sheet of flexible air impervious material folded to provide inner and outer hinge folds connecting said diaphragms and corner sections thereof, a plurality of substantially rigid sheets of plastic material bonded to said flexible material over the outer surface thereof, said sheets of plastic material being sepa rated at the inner and outer folds, and a strip of substantially rigid plastic material bulged outwardly to extend over said outer hinge fold and bonded thereto to permit the flexing of said hinge folds as the bellows is dilated, said plastic strips and sheets providing a protective and finishing surface for said outer hinge folds and the intermediate exposed outer surface of said diaphragms.

4. A rectangular bellows comprising a series of diaphragms formed from a sheet of flexible material folded to provide inner and outer hinge folds connecting said diaphragms merging into pleated corner sections, a plurality of substantially rigid sheets of plastic material bonded to said flexible material over the outer surface thereof, said sheets of plastic material being separated at the inner and outer folds, and a strip of substantially rigid plastic material bulged outwardly to extend over said outer hinge fold and bonded thereto to permit the flexing of said hinge folds as the bellows is dilated, said plastic sheets providing a protective and finishing surface for said outer hinge folds and the intermediate exposed outer surface of said diaphragms, and a series of tapered fingers formed in said sheet of plastic material at each of the corner sections of said diaphragm tapering radially inward to permitcorner formation thereof. I

5. A rectangular bellows having a series of diaphragms formed of inner and outer layers of flexible airimpervious material, said layers being folded to jointly provide an inner hinge fold connecting said diaphragms along their inner edges said inner layer being folded to provide hinge folds connecting said diaphragms along their outer edges and corner sections, a strip of plastic material bonded between said layers having adjacent edges thereof curved inwardly to.

ward each other about a portion of the outer hinge fold formed by said inner layer, and a bead of plastic material curved in cross section secured to said outer layer to embrace and protect the outer hinge fold of the inner layer and the inwardly curved edges of said strips.

6. A rectangular bellows having a series of diaphragms formed of inner and outer layers of flexible air impervious material, said layers being folded to jointly provide inner hinge folds connecting said diaphragms along their inner edges and corner sections said inner layer being folded to provide hinge folds connecting said diaphragms along their outer edges and corner sections, a strip of plastic material bonded between said layers having adjacent edges thereof curved inwardly toward each other about a portion of the outer hinge fold formed by said inner layer, bead of plastic material curved in cross section secured to said outer layer to embrace and protect the outer hinge fold of the inner layer and the inwardly curved edges of said strips, and a strip of plastic material extending over and bonded to the exterior surface of said outer layer intermediate of and extending adjacent to said inner and outer hinge folds.

7. A rectangular bellows having a series of diaphragms formed of inner and outer layers of flexible air impervious material, said layers being folded to jointly provide inner hinge folds connecting said diaphragms along their inner edges and said inner layer being folded to provide "hinge folds connecting said diaphragms along their outer edges and corner sections, said outer layer being looped outwardly beyond said inner layers along said outer hinge folds, outer strips of substantially rigid plastic material secured to said outer layer of each diaphragm intermediate and spaced inwardly of its hinge connections, inner strips of said plastic material secured between the layers of each diaphragm, said inner strips terminating inwardly of the respective inner hinge folds and being partially curved about the outer hinge folds of the inner layer to permit the formation of and to protect said folds, said inner and outer strips having cut away portions at intervals, pleats formed by said material within said cut away portions to provide corners for each of said diaphragms, and

a plastic bead U-shaped in cross section secured about the outer looped portion of said outer layer and curved about the corners of each diaphragm.

8. The method of constructing a rectangular bellows consisting in laying out a sheet of flexible air impervious material having free ends, preoutting and superimposing on said sheet a series of strips of a substantially rigid plastic material with the adjacent longitudinal edges of said strips slightly spaced apart, each of said strips being cut away at spaced intervals so as to provide tapered notches to permit bending the strips into four or more corner formations bonding said strips and sheet together under heat and pressure, folding said sheet in alternating directions intermediate the spaced strips to provide a pleated formation having inner and outer hinged folds defining a series of hinge diaphragms, forming corner sections in said folded formation of hinged diaphragms by bending the folded formation in the planes of its respective diaphragms at the cut away portions of said strips, and securing their free ends together with said corner sections formed therein.

9. The method of constructing a rectangular bellows consisting in laying out a sheet of flexible air impervious fabric having free ends, superimposing thereon a series of strips of a substantially rigid plastic of less width than the bellows diaphragms to be formed having adjacent edges of each pair slightly spaced from each other and provided with cut away corner sections therein, superimposing on said strips and fabric sheet a second flexible fabric sheet looped 1ongitudinally thereof at spaced intervals, superimposing on the second sheet of fabric a series of said plastic strips of substantially the width of the diaphragms to be formed arranged with a slight spacing between their adjacent edges and with their opposite edges lying adjacent the looped portion of said fabric, said last-mentioned strips having corresponding corner section portions cut therefrom, mounting a curved bead-like strip of said plastic over said looped portion, bonding said sheets of fabric and strips of plastic together under heat and pressure, folding said bonded structure in alternating reverse directions intermediate said plastic strips to form said diaphragms connected by reverse inner and outer hinge folds, forming said folded diaphragms into rectangular bellows formation about the corner sections provided in said plastic strips, and securing the free ends thereof together.

EDWARD C. SLOAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 868,157 Bishopric Oct. 16, 1907 1,365,335 Miles Jan. 11, 1921 1,912,931 Clay June 6, 1933 2,126,833 Steinberger Aug. 16, 1938 2,327,790 Hopkins Aug. 24, 1943 FOREIGN PATENTS Number Country Date 164,156 Great Britain of 1921 471,985 Germany of 1929 

